The main discoveries of the Genetic Pharmacology Unit during FY 94 were the following: (1) Increased intracellular cAMP concentration results in up to 7-fold trans-activation of the human D1A dopamine receptor gene promoter in transient transfection assays in SK-N-MC cells. We localized this response to two regions within exon 1 of this gene where nuclear protein interactions were observed. This response appears to be mediated by a novel transcription factor. (2) The in vivo function of a 2.3 kb D1A promoter fragment fused to the lacZ gene was tested in transgenic mice. The progeny of many founders were examined but the distribution of staining was unlike that of endogenous D1A receptors. (3) We found a 130 kDa nuclear protein that binds to the negative modulator of the rat D2 receptor gene in conjunction with Sp1. Current efforts are focused on cloning this protein. (4) In vivo analysis of a 353 bp fragment of the rat D2 gene fused with the lacZ reporter gene in transgenic mice failed to show any blue staining in four lines. (4) We discovered that nuclear extracts from the brains of old rats bind to the promoter region of the D2 gene much less than those from young rats and may explain the decline in D2 receptor expression with aging.(5) In the rat BDNF gene which has multiple alternate first exons, we discovered yet another 5' exon. Quantitation of BDNF transcripts having each of these alternate exons revealed that all are most abundant in the hippocampus, intermediate in nigra and cerebellum, and lowest in striatum. However, the magnitude of these differences varied considerably among the alternate first exons suggesting that BDNF gene transcription in the adult brain is regulated by alternate promoters that are differentially active across brain regions. We also found that increased intracellular calcium levels in the BDNF expressing C6 glioma cells results in up to 10~fold increase in the BDNF message, a response which could be blocked by actinomycin D treatment. (6) BDNF function in the adult rat brain was studied using antisense oligonucleotides. Two days after stereotaxic injection of antisense oligos into the striatum, we observed a 3-fold increase in nigral DA content compared with rats receiving nonsense oligos. Seven days later, nigral DA levels returned to normal while striatal levels increased by 2-fold. These observations add support to the hypothesis that BDNF is critical in modulating the function of the nigrostriatal dopamine system in the adult organism. (7) We determined the sequence of an antisense oligodeoxynucleotide that effectively blocks apolipoprotein E message translation in cultured cells.